burke



(No Model.) -3 sheets-sheet 2.

vC. Gr. BURKE. TELEGRAPHIG SYSTEM.` No. 295.855.. Patented Mar. 2.5, 1884.

WITNESSES INVENTOR.

N. PIETER Phvwumognpiwf, washington D. (L

(No Model.) 3 Sheets-Sheet 3.

G. G. BURKE. TELEGRAPHIG SYSTEM;

No. 295,855. PatentedMar. 25, 1884.

wnNEssx-:s A INVENTOR By his ./ltomeys y. y *fd/MQQMW lllrTTTnn STaTns Param @ei-rien CHARLES G. BURKE, OF RICHMOND HILL, NEV YORK.

TELEG RAPHlC SYSTEM.

SPECIFICATON forming part of Letters Patent No. 295,855, dated March 25, 1884.

Application filed December 17, 1883. (No model.)

,To @ZZ whom it may concern.-

Be it known that I, CHARLns G. BURKE, a citizen of the United States, residing at Richmond Hill, in the county of Queens and State of New York, have invented certain new and useful Improvements in Telegraphic Systems, of which the following is a specilication.

The invention more particularly relates to the class of electric telegraphsk in which the messages transmitted are indicated by the frequency, duration, and character of electric impulses rather than to the class in which electric currents or impulses are employed for actuating or controlling mechanism constructed to print or stereotypethe message in letters or words. The invention is nevertheless also applicable to the last-mentioned systems of telegraphy and telegraphic apparatus.

It has been customary to employ electricimpulses of diiierent lengths, durations, and frequency, combined indifferent ways, for indicating the different let-ters of the alphabet or other characters, and forming the words which embody the telegraphic message. These currents upon traversing the main line of a telegraphic system have heretofore been interpreted or translated into the appropriate letters and words, either by the impressions which they are caused to stereotype upon a receiving-strip of paper, or directly from the movements of an armature of an electro-magnet which is caused to be vitalized thereby. The movements of the armature are rendered sensible by sound, or, as in submarine-cable systems, by the movements of a ray of light reliected from a galvanometer-needle-fsuch an instruinentbeing substituted for the usual form ot electro-magnet. In whatever manner the message is to be interpreted it has been eustomary to employ impulses differing in length, l

in duration, or in polarity, which impulses, either singly or in combination, designate the different letters of the alphabet or other signicant characters.

rIhe object of this invention is to provide a system oftelegraphy morev rapid and less expensive in its operation than those of the character aboveindicated, and which is based upon a principle involving the employment of a less number of separate electric currents or impulses, and which will at the same time destroy or otherwise obviate the detrimental effects produced by the so-called static77 charge and discharge ofthe main line. The invention consists, generally, in dividing the letters of the alphabet into separate and independent groups, preferably seven in number, design ating each oi' the several groups by a particular electric current or combination of currents, and in indicating the individual letters contained in any particular group by the interval of time elapsing after the group is designated before a succeeding groupis designated, which interval agrees in units to the position of the letter in the irst group. For the convenience of the receiving-operator these intervals may be marked or divided into periods or units by means of a metronome,or by any suitable time-measuringdevice capable ol' proper regulation.

The groups may be designated by currents of opposite polarities, currents' of different strengths or of diii-erent durations, or by currents separated by different periods or intervals of time. The particular class of currents to be employed will depend upon the circumstances of any particular case. The transmitting device is organized to transmit these currents in a manner appropriate to indicate the groups as well as the position ot' the letters in the group. This is accomplished by separating each succeeding group from the preceding group by an interval of appropriate duration for indicating the letter. The receivingoperator recognizes the groups, as they are successively denoted, by the eiiects produced by the currents, and the letters by the intervals occurring between the group-indicating currents or combination of currents.

When electric currents of different polarities are to be used-a method which is very efficient in submarine cables and other long lines of telegraph-the transmitting device may be conveniently organized to cause a rotating circuit-closing arm to pass successively beneath the. extremities of two rows of keys arranged in concentric circles, the individual keys in the two rows being placed in the same radial lines, The two series are respectively connected with the positive and the negative poles of two batteries or other convenient source of electricity, and a current of the cor- IOO responding character will be transmitted w hen a key in either series is projected into the path of the circuit-closing arm. Means are provided for regulating the rapidity with which the circuitfcontrolling arm shall revolve, and the period intervening between the passage of the arm from one pair of keys to the next succeeding pair is the same throughout its entire revolution. At the receiving-station an interpreting device of any suitable charactersuch, for instance, as a reflecting-galvanometer-is caused to be actuated by the positive and negative currents, and casts a retlected ray of light in one direction or the other, aceording to the polarity of the current.

Any convenient device-such, for instance, as ametronome regulated to beat once for each pair of keys passed by the circuit-closing arm ofthe trausmitter-may be employed for the purpose of assisting the receiving-opera` tor in measuring the units ottime intervening between the successive groups of signals. A suitable device for enabling the receiving-operator to manually record the letters as they are successively indicated is also located at the receiving-station, and the reflected ray of light is preferably thrown directly upon the keyboard of such an instrument.

Other' obvious methods of designating and interpreting the groups may be used-as, 'for instance, currents or impulses of a given strength may be substituted `for the positive impulses, and of an increased or of a diminished strength for the negative impulses-for the purpose of determining the groups, and these may be interpreted with the aid of two telegraphic sounders adjusted to respond to the respecti ve current strengths. A gain,it may be Afound convenient in some instances to employ currents of two different durationswsuch as are employed for denoting the dots and dashes of the Morse telegraphic code. These group-designating currents may be received directly upon chemically-prepared paper, and subsequently interpreted at the convenience ofthe reeeiving-operator.

It is evident that any of the well-known classes of automatic transmitting devices may be employed-as, for instance, the messages may be perforated or stenciled in a strip of paper and afterward passed beneath a suitable transmitting-stylus.

The letter-groups into which the alphabet is divided are preferably seven in number. The first group, when positive and negative designating-impulses are employed, is designated by a single positive impulse, and the second by a single negative impulse. rlhe third group is designated by a positive followed by a negative imp ulse, and the fourth by a negative followed by a positive impulse. Two positive with an intervening negative impulse signifies the fifth group, and two negative with an intervening positivcimpulse indi i Cates the sixth group. denoted by two positive and two negative im- The seventh group is l pulses alternating with each other. The groups into which it is desirable to dividethe letters of the alphabet in practice are dependent upon the Vfrequency with which they are employed in ordinary composition, l'or it will be evident that it is desirable to designate the groups containing the letters which are most frequently employed by means of the briefer signals. For this purpose the letters are preti erably arranged in the following groups, the numerals referring to the number ofthe group in each instance: I, E A I O, Il, N U T S; Ill, G H l? L; 1V, BY lt D, V, lV M F G; VI, K G- Q V; VII, X Z.

The letters of the alphabet having been thus divided into groups, it will be seen that each let-ter may be further designated, according to the position which it occupies in its group. rlhus E is the first, A the second, l the third, and O7 the fourth letter in the first group. The interval of time, therefore, which elapses after any particular group has been designated by its signal before a succeeding group-signal is received indicates to the receiving-operator some particular letter in that group.

Considering that the letters are to be designated by intervals or units of time elapsing after the group-signal has been transmitted, and that these units are designated by a metronome, the following tabulated form will serve to illustrate, first, the groupsignals, and, second, the units of time or beats of the metronome by means of which the letters are indicated:

It will be understood thus that if it is desired to transmit the word ink77 a single positive impulse is transmitted, designatingI the 'first group. This is followed, after three units of time, by a single negative impulse. The three units indicate the third letter of the first group designatednthat is to say, thelet- IOC) ter i7wand at thesametimethesingle negative impulse designates the second group. A unit of time having elapsed, two negative .with an intervening positive impulse would at the same time point out the first letter, 11, in the second group, and designate the sixth group as being the one from which the succeeding letter is to be chosen. A single unit of time intervening before another current or combination of currents would then designate the letter 1L Anysuitable combination of currents may be employed for indicating the marks of punctu- `ation and spaces-such, for instance, as two positive currents for a period and two negative currents for a space.

lt will be observed that the pulsations employed for indicating the groups are each composed either of a single current or of a series of currents of alternating polarity. Such a combination of currents efi'ectually prevents any detrimental results which have heretofore been encountered from a static condition of the main line or cable.

It is well known that the effect of a current of opposite polarity succeeding any given current is to neutralize thestatic discharge which otherwise succeeds the interruption of the preceding current. lThe time which lapses between the indication of any two successive groups of letters is snflicient to allow the static discharge or" the last current employed to take place before the next succeeding group is in dicated.

NVhen it is desired to employ electric currents of different strengths for furnishing the group-indicating signals, the same system of group-divisions is applied, the positive current being replaced by currents of a given strength, and the negative currents by currents of a greater or of less strength. The currents of different strengths may be of the same or ot" opposite polarity, as desired. Likewise the substitution of currents of different durations may also be effected by assigning a current of a given duration in place of a positive current, and a current of another and distinctive duration in place of a negative current wherever those currents occur in the system iirst described. i In the accompanying drawings, Figure l is a diagram illustrating the method of carrying the invention into execution, in connection with an organization of apparatus especially adapted to submarine-cable systems; and Fig. 2 illustrates certain details in the construction of the transmitting device. Figs. l, lb, and 3 illustrate the construction of the time-measuring instrument. Fig. 4 is a diagramillustrating the invention as applied to a system in which currents of different strengths are employed.

Referring to Figs. l, l, l", 2, and 3, Arepresents a transmitting key-board, which is divided into two insulated series, B B2, yof transmitting-keys. rlhese series are respectively connected with the positive and with the nega tive poles of two batteries, E and E2, by conductors l and 2. The remaining poles of these batteries are connected with the earth by a conductor, 3. The keys in the two rows B and B2 are arranged in the same radial lines, and the distance between the successive keys in each row is the same throughout the circular series. Beneath the keys extends a circuit-closing arm, F,4 which is placed in electrical connection with a main line or cable, L. The circuit-closing arm F is provided with suitable means, preferably an electric motor, for causing it to revolve at a determinate rate beneath the lower extremities of the circuitclosing keys. Each key is constructed, as shown in Fig. 2, with a beveled or rounded extremity, which is normally held out of the path of the circuit-closing arm F by means of a spring entering an annular groove or notch, ft. Each key may, however, be pressed downward, so that its lower extremity will project into the path ofthe circuit-closing arm F. This arm, by striking against the key during its revolution, not only completes the electrical connections of one or the other battery, E or El, with the main line L, accordingly as the depressed key is in the series B or B2, but it also serves to force the key upward again into its normal position' without arresting the movement of the arm. The currents which may thus be transmitted by means of the keyboard to the main line are caused at the receiving-station to traverse the actuating-coils of a retlectiiig-galvanometer, G, of well-known construction. The movements of the galvanometer-needle are rendered apparent by means of the movements thus imparted to a ray of light falling upon a mirror, g, which is supported upon the arbor of the galvanometer-needle. Such a ray of light is, for convenience, reflected upon a key-board, hereinafter described, and is bent toward the left hand or toward the right, accordingly as the actuating current or impulse is of positive or negative polarity.

The galvanometer shown in the drawings consists of a permanent magnet, g', between the poles of which is delicately suspended a needle, g2. Surrounding the needle is a coil of insulated wire,g3,the convolutious ot which extend in the direction parallel with the normal direction of the needle g2. A current of a given polarity traversing the coils g3 serves to deflect this needle in one direction, and a current of opposite polarity deiiects the same in the opposite direction. The ray reiiected by the mirror g is derived from a llame, g4, and is preferably cast, as before stated, upon a key-board, l?, though it may be received upon an independent screen. By the movements of this reliected ray the polarities of the currents transmitted are readily determined by the operator. The receiving-operator may therefore readily determine the particular group of letters at any time selected by the transmittingoperator, and by measuring the intervals which elapse between the successive IOO groups he determines the particular let-ters selected. By means of a metronome the intervals may be conveniently divided into units equal to the time occupied by the circuit-clos ing arm in passing from one pair ot' keys in the transmitter to the next succeeding pair. Such a device is shown at H, Fig. l", and it may be ol' any convenient construction. In the construction shown a revolving wheel, h', is driven at a constant rate by means of a weight, h. From the periphery of this wheel extends a series ot' equidistant radia-l pins, h, which are successively engaged by means of a vibrating escapenient, 7i. This escapcment consists of two teeth, h5 and h, respectively, facing each other, but in different planes, and carried upon one arm ofthe vibrating pendulum lf. Suilicient distance intervenes between the planes in which the edges of the teeth h5 and Il are placed to permit the passage ot' the teeth or pins h between them when the pendulum is vibrated laterally. Upon the pendulum-rod are carried one or more weights, h and It, which may be adjusted l'or modifying the rapidity with which .it will be vibrated under the in lluence ofthe wheel h. The sound obtained by the striking ofthe successive pins against the teeth ot' the cscapement is employed for measuring the successive beats, and thus the units of time into which the intervals are divided. There is also placed at the receiving-station a recording-instrnment,which may consist oi any suitable form ol'l type-writer. The key-board of this instrument is preferably arranged as indicated at I?. Considering the line p to be the center of the board, the keys in the lower left-hand line, commencing at the left extreme, are designed to represent the letters contained in the iirst groupnamely, e a io.77 Theline above represents the letters in the third group-namely, c h p l.77 Likewise the line next above represents the letters w m f g, and the two keys in the upper line represent x z. The keys arranged upon the right-hand side ol3 the central line indicate in the same manner the letters contained in the right-hand groups. It

will be seen that the groups comprised upon the two sides of the board are arranged ac cordingly as the iirst impulse oi' current cmployed for representing the group is a positive current or a negative current, those represented by a positive primal current being upon the lett-hand side ot' the board, and those by a negative primal current upon the righthand side. In the central line two keys, p and p2, are placed, which are respectively designed to represent a space and a period.

At a convenient place upon the keyboard I? is formed a scale or plane surface, P', upon which the ray of light from the galvanonleter is reflected. This construction renders it convenient for the operator to watch the movements ofthe ray while he is operating the keys. An independent screen may, however, be substituted for thislast-named construction.

In practice, also, the operator may in some instances dispense with the mirror and re ilected ray ot light and determine the groups by watching the movements ol" the galvanometer-needle, for it will be readily understood that it is not necessary to observe the degree of movement ot' the needle, but merely its direction.

Thus far the description ofthe drawings has been given in connection with the use of electric currents distinguished from each other by their polarity. A method of adapting the invention to apparatus organized to employ electric currents oldiiferent strengths will be described in connection with Fig. et. In this organization a single battery. E, is substr tuted tor the batteries Il and One polesay the negativeis connected with the earth by a conductor, Ll, and the remaining pole is provided with two conductors, 5 and 6, respectively leading to the series B and L oi' transmitting-kcys. In one of these conductors, 6, is included an artificial resistance, It, adapted to reduce the currents which are transmitted to line by means ot' the keys B2. The two classes ot' current thus obtained may, for convenience, be considered as having the one' double the strength oi" the other. At the receiving-station these currents are caused to actuate one or the other ot' two relays, S' and Si, which are respectively adjusted to respond to currents transmitted through the agency ot" the keys B and These relays inay be of any well-known i'orm. In the drawings, the relay S is represented as an ordinary electromagnet, with an armature-lever, s', which is adjusted to respond to electric currents of the strength transmitted by the series of keys B', but not of the strength transmitted by the series B. The connections ot' a local circuit, including a sounder, T, are designed to be completed by this relay, when the armature s is against its front contact-stop. The relay SIl is provided with an armature-lever, s, and a supplemental lever, s, against which it strikes when at tracted by its electro-magnet- The armaturelevcr s is adjusted to respond to currents ot' the strength transmitted by the action ot' the series of keys B2. \Vhen, however, a current of the strength transmitted by the keys'B traverses the main line, the armature is attracted with sutlicient force to aetnate the supplemental lever s also, and to impel it away from its back contact-stop, s". A local circuit, including a sounder7 T2, has its terminals respectively connected with the armaturelever s! and the stop s". The connections ot this circuit will therefore be completed only through the intluenee ot' currents transmitted by the series ot keys B2.

The two sounders T' and T2 are respectively placed near the opposite extremities ofthe receiving keyboard I), and the receiving-open ator will be able to readily determine the groupsignals from the action of these Sounders in the IIO same manner as described with reference to Figs. 1, l, l", 2, and 3.

The theory of the invention may be still further carried out by substituting for the currents of opposite polarity,or the currents of dit ferent strengths, currents of other distinctive characteristics.

It is evident that numerals may be added to the series of letters and indicated by groupro signals in the same manner as described, and

that the combinations of currents may be indefinitely extended.

I claim as my inventionl. Thehereinbefore-described method of te legraphymfhich consists in distinguishing different groups o' characters by an electric current, impulse, or combination of electric currents or impulses, and the individual letters contained in such groups by distinctive interzo vals of time occurring after the group-signal has been given and before a succeeding signal is commenced.

2. The hereinbefore-described method of telegraphically indicating different characters of a series which consists in dividing such series into arbitrary groups, designating` each of the several groups by means of electric currents possessing particular characteristics, and indi cating the individual letters in the several 3o groups by different intervals of time succeeding the group-designating currents.

3. Thehereinbeibre-described method of telegraphy which consists in indicating different groups of letters or characters by electric cur- 3 5 rents of distinguishing characteristics, and in dicatin g the individual characters by different numbers of units of time elapsing after such groups are indicated, substantially as described.

4. Thehereinbefore-described method of telegraphy, which consists in designating each particular group of letters bythe transmission of electric currents or impulses,y and each individual letter in such group by the interval elapsing before the transmission of a succeeding current or impulse.

5. rlhe hereinbeibre-described method of in. dicating the individual characters of a series, which consists in indicating the groups into which said series is divided by electric cur- 5o rents, and assigning to each character in each group a distinctive period of time by the occurrence of which, after the group has been indicated, that character is designated.

6. The hereinbefore-described method of indicating the different characters in a series, which consists in dividing such series into groups, designating each ofthe different groups by a characteristic signal, and yindicating the individual characters in such groups by the measurements of a metronome. n

7. The hereinbeforedescribed method of transmitting telegraphic messages,which consists in indicating different groups of character-recording keys, corresponding to the characters which constitute an embodiment of such message, by predetermined electric signals, and indicating the particular recording-key in a designated group by the interval occurring after such group has been designated before another signal is commenced.

8. The hereinbeioredescribed method of indicating the different keys of a character-recording keyboard which correspond to the characters embodying a telegraphic message, which consists in indicating the side of such board upon which such keys are located by primal signals, the particular line of keys con taining such keys bythe same primal signal, or a combination therewith of other signal or signals, and the particular key in such line by the units of time measuring the intervals between the signals or combination of signals.

9. The hereinbeibre-described method of indicating the different characters contained in a series,which consists in designating different groups of said series by the movements of a reflected ray of light, and indicating the diiierent characters contained in suc-h groups by the period during which the direction of such ray of light is unchanged.

In testimony whereof I have hereunto subscribed my name this 15th day of December, A. D. 1883.

CHARLES G. BURKE.

Witnessesz DANL. W. EDGEOOMB, CHARLES A. TERRY. 

